Peroxisome proliferator-activated receptor (PPAR) is a member of the nuclear receptor superfamily of ligand activated transcription factor. Three subtypes of PPAR, i.e., PPAR α, PPAR γ, and PPAR δ, have been cloned from mouse and human. PPAR is an important nuclear hormone receptor for the metabolism of carbohydrate and lipid, cell growth and differentiation, phenotype conversion, apoptosis, angiogenesis, immunoregulation, and inflammatory reaction. Compounds that activate PPAR are useful for the treatment or prophylaxis of various clinical diseases such as metabolic syndrome, obesity, prediabetes, type 2 diabetes and the other insulin resistance syndrome, hypertension, atherosclerosis, lipemia, inflammatory skin diseases such as psoriasis, inflammatory bowel disease, and inflammatory neurodegenerative diseases such as multiple sclerosis, Alzheimer's disease etc., proliferative diseases such as benign or malignant tumor, metastatic tumor or the like, or the like. PPAR γ specifically plays an important role in adipocyte differentiation. Hypertrophic adipocytes secrete large amounts of a cytokine such as TNF-α, and free fatty acid which induce insulin resistance. On the other hand, thiazolidinedione derivatives such as pioglitazone, rosiglitazone or the like improve insulin resistance by activating PPAR γ to decrease hypertrophic adipocytes by apoptosis, and promoting differentiation of preadipocytes into small adipocytes having normal function (non-patent documents 1 and 2). Pioglitazone and rosiglitazone, which are PPAR γ agonists, have already been clinically used as therapeutic drugs for diabetes (patent documents 1 and 2).
PPAR γ agonists are also useful as agents for treating and/or preventing diseases besides diabetes, such as metabolic syndrome, obesity, impaired glucose tolerance and other insulin resistance syndrome, which are prediabetic conditions, hypertension, atherosclerosis, hyperlipidemia, inflammatory diseases such as psoriasis or the like, inflammatory bowel disease, or the like. It has also been reported that it is useful as a therapeutic and/or prophylactic agent for proliferative diseases such as benign or malignant tumor, metastatic tumor, or the like (non-patent documents 3, 4).
It has been reported that selective partial agonists against PPAR γ do not accompany side effects such as body weight increase, adipocyte accumulation or the like, as compared to the existing full agonists (thiazolidinedione derivative or the like) (non-patent document 5).
A tricyclic compound represented by the following formula (A) and a derivative thereof are known as PPAR agonists/antagonists/regulators (patent document 3).

It is known that a compound represented by the following formula (B), which is a tricyclic compound, and a derivative thereof have a superior hypotensive action based on an angiotensin II receptor antagonistic action (see patent document 4).
